In November 2002, the first of three outbreaks of Salmonella Montevideo infection in Australia and New Zealand was identified in New South Wales, Australia. Affected persons were interviewed, and epidemiologically linked retail outlets inspected. Imported tahini was rapidly identified as the source of infection. The contaminated tahini was recalled and international alerts posted. A second outbreak was identified in Australia in June–July 2003 and another in New Zealand in August 2003. In a total of 68 S. Montevideo infections, 66 cases were contacted. Fifty-four (82%) reported consumption of sesame seed-based foods. Laboratory analyses demonstrated closely related PFGE patterns in the S. Montevideo isolates from human cases and sesame-based foods imported from two countries. On the basis of our investigations sesame-based products were sampled in other jurisdictions and three products in Canada and one in the United Kingdom were positive for Salmonella spp., demonstrating the value of international alerts when food products have a wide distribution and a long shelf life. A review of the controls for Salmonella spp. during the production of sesame-based products is recommended.

The Stonehouse meningitis survey took place in 1986 [1]. The context was a substantial and highly focal outbreak of meningococcal disease affecting the population of southern Gloucestershire and particularly the town of Stroud and its adjacent communities – a population of some 90000 individuals in the west of England. Almost all cases of meningococcal disease were due to a serogroup B, type 15, subtype P1.7,16 sulphonamide-resistant strain that had not been documented in Gloucestershire (and only rarely in the United Kingdom) prior to 1982, the first year of the outbreak. As is often the case at the start of an outbreak of meningococcal disease in a temperate country, the attack rate rose particularly in older children. For the population of Stroud as a whole the meningococcal disease attack rate rose from approximately 1·0 cases per 105 to approximately 8 per 105 population.

A mathematical model was used to evaluate the impact of the Italian Measles National Elimination Plan (NEP), and possible sources of failure in achieving its targets. The model considered two different estimates of force of infection, and the possible effect on measles transmission of the current Italian demographic situation, characterized by a below-replacement fertility. Results suggest that reaching all NEP targets will allow measles elimination to be achieved. In addition, the model suggests that achieving elimination by reaching a 95% first-dose coverage appears unlikely; and that conducting catch-up activities, reaching high vaccination coverage, could interrupt virus circulation, but could not prevent the infection re-emerging before 2020. Also, the introduction of the second dose of measles vaccine seems necessary for achieving and maintaining elimination. Furthermore, current Italian demography appears to be favourable for reaching elimination.

To assess rubella and measles susceptibility among women of childbearing age we conducted a cross-sectional seroprevalence study in four cities and one rural area in Argentina. A convenience sample of women aged 15–49 years seeking care in public health-care institutions was selected (n=2804). Serum specimens were tested for rubella and measles IgG antibody titres. The overall susceptibility to rubella and measles was 8·8 and 12·5% respectively. Seroprevalence differences were found for both rubella (P<0·001) and measles (P=0·002) across sites. Rubella seroprevalence was higher in women aged [ges ]40 years than in younger women (P=0·04). Measles seroprevalence tended to increase with age (P<0·001). Approximately 15% of women aged 15–29 years were not immune to measles. No risk factors were associated with rubella seronegativity; however, age (P<0·001) and having less than four pregnancies (P<0·001) were factors associated with measles seronegativity. Our findings support the introduction of supplemental immunization activities targeting adolescents and young adults to prevent congenital rubella syndrome and measles outbreaks over time.

The annual incidence of typhoid fever in Taiwan was 2·1–3·6 cases per 1000000 population from 1995 to 2002. More than 80% of 45 patients with typhoid fever treated at National Taiwan University Hospital from 1996 to 2002 had elevated serum aminotransferase levels at presentation. Ten of these patients were treated during an outbreak in Taipei County in 2002, and seven of them who did not have pre-existing liver disease developed hepatitis, which was unrelated to other aetiologies. All Salmonella typhi isolates were susceptible to extended-spectrum cephalosporins and fluoroquinolones. Multidrug resistance (intermediate resistance to ampicillin, trimethoprim–sulphamethoxazole, and chloramphenicol) was found in one (2·5%) of the 40 isolates studied. Pulsed-field gel electrophoresis analysis demonstrated a high genetic diversity among S. typhi isolates and identified a novel clone associated with the 2002 outbreak. Physicians should be alert to the possibility of typhoid fever when patients, without other gastrointestinal symptoms, present with sustained fever and hepatitis.

Predicting the impact of infectious diseases on the well-being of the community is a cornerstone of identifying effective prevention, control and support. One only has to reflect on the last few years in the United Kingdom to see the impact mathematical modelling has had on public and government, with controversy around the likely numbers of sufferers from new-variant Creutzfeld–Jakob disease, human immunodeficiency virus, and continuing debate as to whether to use vaccine to support control of foot-and-mouth disease. Over the last 20–25 years, Epidemiology and Infection, and before it the Journal of Hygiene, have published many of the sentinel papers in the mathematical modelling of infectious disease, both in humans and animals. The discipline has advanced from relatively simple analyses to the most complex assessments whose underlying mathematics and statistics almost certainly exceed the comprehension of all but a few microbiologists and public health specialists. The depth of the analysis does not obscure the key messages, however, for the epidemiology of infectious disease and its control, and a Special Article in the journal in 1988 overviewed its contribution [1].

Melioidosis is an infectious disease caused by Burkholderia pseudomallei. It is endemic in South East Asia and tropical regions of Northern Australia. Sporadic cases have been described elsewhere. In this article we present a case of acute pulmonary melioidosis with fatal outcome imported from Brazil. The most common pathogen causing severe community-acquired pneumonia in Brazil is Streptococcus pneumoniae. Other possible pathogens include Legionella spp., Mycoplasma pneumonia, Gram-negative rods and viruses. There are few reports of melioidosis in the Americas. This article represents the second known human case of melioidosis from Brazil. Recognition of melioidosis as a possible cause of severe pneumonia, even if a patient has not been travelling in a highly endemic area, is important because of the therapeutic consequences. The epidemiology of melioidosis will be reviewed.

Of a total of 508 stool specimens from children with acute diarrhoea, mostly under the age of 5 years, collected in nine cities in the western and southeastern regions of Turkey between May 2000 and October 2002, 119 (23·4%) were found positive for rotaviruses (RV) by ELISA. Positive samples were characterized by electropherotyping and G and P genotyping. A subset of G and P types were confirmed by nucleic acid sequencing. The most prevalent types found in this collection included G4P[8], accounting for 27/64 (42·2%) of the fully characterized strains. G1P[8], G2P[4] and G3P[8] were found in 17 (26·6%), 2 (3·1%) and one (1·5%) samples respectively. Less common strains such as G9P[8] were found in two (3·2%) samples and G2P[8], G1P[6], G2P[6] and G4P[6], possible reassortant viruses, were found in five (7·8%), 2 (3·1%), one (1·5%) and four (6·3%) samples respectively. Mixed infections were found in six (7·3%) samples and were associated with combinations of G1+G2, G1+G4, G1+G9 and G4+G9 strains. This is the first molecular epidemiology study of its kind to be carried out in Turkey and suggests a significant diversity of co-circulating rotavirus strains.

We reviewed measles surveillance data for 1993–2002 to determine the impact of Australia's measles control initiatives. The introduction of a second dose of measles–mumps–rubella (MMR) vaccine for 10- to 16-year-olds in 1993 was followed by marked reductions in measles notifications and hospitalizations, especially in the targeted age group. Further rate reductions were achieved following the Measles Control Campaign (MCC) in 1998, which involved a catch-up campaign for primary-school-aged children and lowering the age for the second dose of MMR vaccine to 4 years. Since the MCC, outbreaks have continued to occur, but most had a source case who was infected overseas, which suggests that indigenous transmission has been interrupted. In addition, a greater proportion of cases have been in adults although infants aged <5 years still had the highest rates. In conclusion, Australia is making good progress towards measles elimination. However, as in other countries, this progress can be sustained only by maintaining high vaccination coverage with the routine childhood vaccination schedule.

This prospective, multicentre study was conducted during 2–30 April 2001 in the internal medicine/infectious diseases services in France and included data from 1858 hepatitis C virus (HCV)-infected patients, half of whom were HIV co-infected. The aims were to outline the type of pre-therapeutic evaluation of HCV infection performed (HCV RNA, genotype, liver biopsy); determine the proportion and characteristics of patients receiving antiviral treatment; and determine if any changes in these parameters had occurred between 1995 and 2001. Patients whom had a complete pre-therapeutic evaluation (39%, 709/1834) and received antiviral treatment (38%, 690/1830) were more likely to have abnormal liver biochemistry, cirrhosis and cryoglobulinaemia (P<0·001). Injecting drug users and HIV-co-infected patients were less likely to have a complete pre-therapeutic evaluation or receive antiviral treatment (P<0·001). A complete pre-therapeutic evaluation was more often performed in 2001 than in 1995 (39% vs. 6%, P<0·001), including qualitative HCV RNA testing (91% vs. 68%, P<0·001), genotyping (59% vs. 7%, P<0·001) and a liver biopsy (60% vs. 29%, P<0·001). The frequency of anti-HCV treatment approximately doubled between 1995 and 2001 (20% vs. 38%, P<0·001). Although adherence to consensus recommendations regarding pre-therapeutic evaluation is not ideal, a substantial improvement has occurred since 1995. Nevertheless, means of increasing the availability of antiviral therapies, particularly for patients with HIV co-infection or injecting drug use, require further study.

The frequency of meningitis due to penicillin-resistant Streptococcus pneumoniae (PRP) has increased in recent years, making treatment failure more likely. It is currently expected that pneumococcal conjugate vaccines might curb this trend. We investigated this issue using a mathematical model applied to the current prevalence of resistance and antibiotic exposure in the United States and in France. Our main finding was that the level of antibiotic exposure may limit the effect of the vaccine. In relatively low antibiotic exposure environments such as the United States, large-scale vaccination prevents a large part of PRP meningitis cases, whereas in high antibiotic-exposure environments such as France, vaccination alone does not lead to a substantial reduction in PRP meningitis incidence. Our results suggest that antibiotic exposure reduction will remain of primary importance for the control of PRP meningitis despite wide scale use of pneumococcal conjugate vaccines.

Epidemiology & Infection probably attracts more papers on mathematical modelling of infectious diseases than does any other epidemiology journal. The most important modelling papers published in the journal were probably those of Anderson and May during the 1980s, which laid the foundations for much of the subsequent modelling work carried out by themselves and their colleagues. Since the start of their partnership, they authored 17 articles between them in the journal, including work quantifying the effect of different vaccination strategies against measles and rubella [1, 2], on the epidemiology of rubella in the United Kingdom [3], and on the effect of age-dependent contact between individuals on the critical level of vaccination coverage required for control [4]. The latter work, published in 1985, was particularly important, since it described methods for incorporating realistic assumptions about (heterogeneous) mixing between individuals into models, an issue which was beginning to be addressed in the mathematical literature but which had not yet reached many epidemiological journals. Other important modelling work published in Epidemiology and Infection includes that of McLean et al. (reproduced in this edition) on the control of measles in developing countries [5, 6], and by Garnett and Grenfell on the epidemiology of varicella zoster in developed countries [7, 8].

An outbreak of influenza A occurred in a prison system in New South Wales, Australia in January 2003 during the southern hemisphere summer. This report documents only the third confirmed outbreak of influenza in a prison environment. The outbreak investigation included case ascertainment, state-wide surveillance, a case-control study and interventions to limit the outbreak such as infection control, quarantine, cohorting of cases, and the use of antiviral medication for prophylaxis. A total of 37 clinical cases were identified. Influenza A virus was detected in 11 of the 22 respiratory tract specimens collected. The virus was typed as an influenza A/Fujian/411/2002 (H3N2)-like virus. This strain subsequently became the predominant virus strain during the northern hemisphere winter and the following 2003 Australian southern hemisphere winter influenza season.

We evaluated all fatal neonatal sepsis and pneumonia cases occurring in Alaska during 1992–2000. Risk factors were evaluated using a database of all births occurring during the study period. Of 32 cases, group B streptococcus (GBS) was isolated from 21% (all <7 days of age), Candida spp. from 19% (all >7 days of age), non-GBS Gram-positive bacteria from 50% (53% <7 days of age), and Gram-negative infections from 38% (58% <7 days of age). Infants born at <37 weeks gestation accounted for 72% of cases and had an increased risk of GBS [rate ratio (RR) 9·1, 95% confidence interval (CI) 2·0–41] and non-GBS (RR 40, 95% CI 16–101) disease. Neonatal sepsis mortality has become an outcome concentrated among pre-term infants. Aetiologies include GBS during the early neonatal period, Candida spp. during the late neonatal period, and other bacteria during both periods.

Serological and virological features of dengue fever (DF) and dengue haemorrhagic fever (DHF) in Thailand were analysed in 2715 patients from 1999 to 2002. The illness was caused by DEN-1 in 45%, DEN-2 in 32%, DEN-3 in 18% and DEN-4 in 5% of patients. Almost all of the DHF cases caused by DEN-2 and DEN-4 were in secondary infection, while approximately 20% of the DHF cases caused by DEN-1 and DEN-3 were in primary infection. Male[ratio ]female ratio and age distribution were not different among four serotypes in primary and secondary infections. These results indicate that DEN-1 and DEN-3 induce DHF in both primary and secondary infections, and suggest that DEN-2 and DEN-4 in Thailand are less likely to cause DHF in primary infections.

We sought to determine the prevalence and associated characteristics of hepatitis A, B, C and D viruses and HIV infections in a prison in Durango, Mexico. Sera from 181 inmates were analysed for HAV antibody, hepatitis B core antibody (HBcAb), hepatitis B surface antigen (HBsAg), HCV antibody, HDV antibody, HIV antibody and HCV genotypes. Prevalence of HAV antibody, HBcAb, HBsAg, HCV antibody, HDV antibody and HIV antibody were 99·4, 4·4, 0·0, 10·0, 0·0 and 0·6% respectively. HCV genotype 1a predominated in HCV-infected inmates (62·5%), followed by HCV genotype 1b (25%) and HCV genotype 3 (12·5%). An association between HBV infection and age >30 years was found. HCV infection was associated with being born in Durango City, history of hepatitis, ear piercing, tattooing, drug abuse history, intravenous drug use and lack of condom use. We concluded that the prevalence of HAV, HBV, HDV and HIV infections in inmates in Durango, Mexico were comparable to those of the Mexican general population and blood donors, but lower than those reported in other prisons around the world. However, HCV infection in inmates was higher than that reported in Mexican blood donors but lower than those reported in other prisons of the world. These results have implications for the optimal planning of preventive and therapeutic measures.

Serological assays using dried blood spots from 5221 women in rural areas of eastern Zimbabwe were used to assess the epidemiology of Trichomonas vaginalis infection, and its association with HIV. Antibodies to T. vaginalis and to HIV were detected by enzyme immunoassays. Behavioural and demographic data were collected by confidential questionnaires. In total, 516 (9·9%) women were seropositive for T. vaginalis and seroprevalence increased with age among younger women. Divorced, widowed and single women were more likely to be seropositive. After controlling for age, seropositivity was significantly associated with being sexually active, having multiple sex partners, having a partner who had multiple sex partners, and having a new sex partner in the past year. Seropositivity was associated with a recent history of genital discharge. Overall, 208 (40·3%) T. vaginalis-positive samples were also positive for HIV, compared with 1106 (23·5%) T. vaginalis-negative samples (age and sex adjusted OR 2·11, 95% CI 1·74–2·55, P<0·001). There was increased risk for being HIV-positive amongst T. vaginalis-seropositive women regardless of residence, employment or education. In a logistic regression controlling for common risk factors, the association remained significant. T. vaginalis-seropositive young women with a history of genital discharge were much more likely to be HIV-positive than women who were T. vaginalis-seronegative and had no history of discharge (OR 6·08, 95% CI 2·95–12·53). Although a causal relationship cannot be assumed, detection and treatment of trichomoniasis may be important in strategies to reduce HIV transmission through sexually transmitted infection control.

The primary aim of this study was to detect and genotype Campylobactercoli strains from humans over a period of one year from November 2002 to October 2003. Campylobacter spp. were isolated from patients with symptoms of enteric infection. Amplified fragment length polymorphism (AFLP) analysis was used to identify the genetic diversity of C. coli strains by cluster analysis. A total of 18·6% of all Campylobacter isolates were identified as C. coli. These data show, that C. coli is indeed of importance to human campylobacter infections. Heterogeneous patterns were detectable among the human C. coli pool by AFLP analysis suggesting different sources of infection. A continuous seasonal shift of genotypes was detectable.

Susceptibilities to amphotericin B and fluconazole of 628 clinical yeast strains collected from 22 hospitals in Taiwan were determined. A total of 53 isolates (8·4%) were resistant to fluconazole. Each hospital had different resistance rate to fluconazole ranging from 0% to 24%. None of the 186 isolates from eight of the 22 hospitals was resistant to fluconazole. In contrast, isolates from nine of the remaining 14 hospitals had greater than 10% resistance rate to fluconazole. Consistently, 88·9% (8/9) fluconazole-resistant C. albicans isolates were from hospitals having a high resistance rate to fluconazole. The prevalence of various Candida spp. in each hospital was different. A positive association was found between the prevalence of C. tropicalis and the resistance rate to fluconazole for individual hospitals. Although only three isolates (0·5%) were resistant to amphotericin B, a co-resistance to both amphotericin B and fluconazole was observed, which highlights the emerging problem of drug resistance.

Asymptomatic carriage of Neisseria meningitidis is common (5–35% of individuals) while the incidence of invasive meningococcal disease is fairly low (<1–5 per 100000 per annum in Europe). Naturally acquired protective immunity may account for this difference. In this study, we investigated the relationship between anti-meningococcal salivary IgA and age and carriage. We showed that salivary IgA to a range of meningococcal antigens increased successively with age with some specificity for commonly circulating serosubtypes. In a group of 258 students 37 (14%) of whom were carriers of N. meningitidis serogroup B, higher levels of specific IgA were associated with carriage. Stratified analysis revealed a positive relationship between smoking and specific anti-N. meningitidis IgA independent of current carriage, weighted odds ratio (OR) 4·1 (95% CI 1·1–18) and OR 3·8 (95% CI 0·96–16) for reference strains B:1:P1.14 and B:4:P1.5,4 respectively. These data implicate IgA as a factor in host defence from meningococcal invasion, although the precise mechanisms remain uncertain.